Electrical meter having its spiral springs protectively



C. G. ROPER ELECTRICAL METER HAVING ITS SPIRAL SPRINGS PROTECTIVELY SURROUNDED BY ZERO SETTING CAGE STRUCTURE Filed Aug. 7, 1962 2 Sheets-Sheet 1 mw s A 0m I w n s e Y i T.

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a ZWQ C. G. ROPER Nov. 3, 1964 3,155,906 ELECTRICAL METER HAVING ITS SPIRAL SPRINGS PROTECTIVELY ZERO SETTING CAGE STRUCTURE SURROUNDED BY Filed Aug. 7, 1962 2 Sheets- Sheet 2 INVENTOR. (710/166 6 Paper HTTOENEYS United States Patent 3,155,906 ELECTRICAL METER HAVING ITS SPIRAL SPRINGS PRQTECTIVELY SURROUNDED BY ZERO SETTING CAQE STRUtITURE Charles G. Roper, Fairfield, Conn., assignor, by mesne assignments, to C. Garland Roper, Fail-field, Conn. Filed Aug. 7, 19 62, Ser. No. 215,355 9 Claims. (Cl. 324-154) The present invention relates to meters and more particularly to electric meters of the type disclosed and claimed in my copending application Serial No. 122,274, filed July 6, 1961.

It is an object of the present invention to provide a novel armature construction which is easy to assemble, simple in construction and reliable in operation and adjustment.

A feature of the invention resides in the novel arrangement of the torsion springs for controlling the position of the armature with respect to the field, and particularly in a novel cage structure for mounting the outer end of the spring for adjustment whereby criticality of spring length is eliminated and less expensive springs can be used.

Another feature of the invention is the construction of the armature from simplified elements which aid in better balancing of the armature.

Other features and advantages of the invention will be apparent from the specification and claims when considered in connection with the accompanying drawings, in which:

FIGURE 1 is a top view of the meter, partly in section, with a top portion of the cover cut away.

PEG. 2 is a side view of the meter, partly in section, with part of the side wall of the base cut away.

FIG. 3 is a section of the meter taken along line 3-3 of FIG. 1.

FIG. 4 is a top view of the mounting means for the cage taken along line 4-4 of FIG. 3.

FIG. 5 is a view taken along line 55 of FIG. 3 showing the bottom cage mounting.

FIG. 6 is a fragmentary sectional view taken through the cage and mounting therefor showing the interlock between the cage and mounting member.

As shown in the drawings, the casing or housing 10 has a meter unit 11 mounted therein. The casing is similar to that shown in my copending application and includes a base section 12 having upstanding side walls 13 and a cover section 14 having depending side walls 15 for sliding into and frictionally engaging the walls of the base section as shown in FIG. 3. The walls of the casing section are inturned at their ends at 1311 to provide shoulders for cooperating with lugs 15.: on the Walls 15 to provide means for quickly and easily mounting a terminal block 16 having meter terminals 16a at one end of the casing. by a window 17 mounted therein to extend thereacross and held in place by cooperating portions of the base and cover section.

The meter unit includes a magnetic structure similar to that disclosed in my copending application and includes a thin, relatively fiat wafer 18 of permanent magnetic material, such as ceramic or nic tel alloy material, and is provided with soft iron pole pieces 19, 29 which are substantially fiat and can be formed by stamping or the like. The pole pieces are secured to opposite faces of the wafer and the lower pole piece has an extension 25 at one side thereof projecting beyond the wafer, and the upper pole piece has an arcuate extension 26 overlying the extension 25 and forming therebetween an gap 27. g

This construction, as noted in my prior application,

The other end of the casing is closed 3,155,905 Patented Nov. 3, 1964 ice produces a uniform magnetic field having an abundance of magnetic lines of fiux and the parallel pole pieces a threaded bore Stia therein carrying opposed adjustable pivot assemblies 31. Secured to the leg 28b of the U is a top disk of plastic insulating material 32 having a central aperture 32a which is force fit over the bushing and is also adhesively secured to the frame to'anchor it 'in position thereon. .A bottom disk 33 is also carried by and secured to the leg 28a of the U by having a central aperture 33a force fit over the bushing.

Mounted on the undersurface of the top disk so asto depend therefrom is an elongate wound coil 35 which de pends from the disk. The armature is pivotally mounted on the meter by central bearing means 36 disposed within a sleeve 37 carried by a bracket 38 carried by one of the pole pieces and locates the sleeve within the U-shaped frame and between the pivot assemblies 31 so that the coil, as shown in FIG. 3, surrounds the extensicn 26 to move thereover with one long side 35a of the coil disposed in the air gap. This arrangement of air gap and coil provides for linearity of the meter and ease of adjustment of the coil with respect to the air gap since only one of the sides of the coil is located within the air gap.

Mounted on each end of the armature, preferably by being force fit on the bushings 30, is a connector ring or member 39 having a lug 40 extending therefrom to be connected to the inner end of torsion springs 41, 42 disposed over the top disk and bottom disk as shown in FIG. 3. The torsion springs are oppositely spiraled to minimize undesirable deflection of the armature with temperature changes.

Heretofore, such springs have had their other ends mounted in fixed relation to the mounting means for the armature and have required springs of accurate lengths in order to provide the desired torsional effect on the armature. The present invention overcomes this requirement by providing a novel mounting of the other ends of the springs which permits the use of springs of varying length and provides for substantial adjustments thereof. As shown in the drawings, a pair of insulating members 43, 44 are fixedly mounted on the meter and have central apertures 43a, 44a adapted to surround the torsion springs as they overlie the disks 32, 33. While the insulating members maybe mounted in various ways, in the illustrated form of the invention the bottom insulating member 43 is fastened by cement or the like to the bottom of the pole piece 25, as shown in FIG. 3, while the upper member 44 is mounted by a pair of posts 45 extending upwardly from the extension 25 and outwardly of the path of movement of the movable coil as shown in FIGS. 1, 2 and 4.

A cage 46 is provided on each mounting member and comprises a circular member 4'] having a central aperture 48 adapted to surround the torsion spring. The cage interlocks with said apertures 43a, 44a and is rotatably mounted thereon. In the illustrated form of the invention the interlocking means comprises ears 49 extending, from the cage inwardly through the aperture 43a or 44a and then folded back, as shown in FIG. 6, to interlock therewith while permitting the cage to be rotated on the member. Each cage is provided with an extension or handle 59 for facilitating the rotation of the cage on the mounting member. The outer end of each spring is secured to the ear closest to it when it is in its normal position and, since there are four ears, springs of varying length can be used. The torsion in the spring can be regulated accurately by rotating the cage on the member. The cage thus arranged eliminates the necessity of having an accurate length on the spring since it can be connected to whatever part of the cage it terminates and thus commercial springs can be used, thus reducing the cost of the material, and also the cage in surrounding the spring will protect it against damage.

In some instances it is desirous of utilizing the torsion springs as the conductors for supplying the current to the armature coil. In this case the connector ring or member 39 is made of conducting material and is provided with an additional lug 46a which extends therefrom and through an aperture 51 in each of the insulating disks 32, 33 and is connected to the terminal of the coil as shown in FIG. 3, and the cages are connected by conductors 52 connected to the handles 50 and to the terminals 16a of the terminal block, as shown in FIG. 1, so that when the terminals 16a are connected across a source of electrical.

energy the coil is energized and, cooperating with the magnetic field, will cause the armature to move about its pivots.

The U-shaped frame of the armature has a lateral projection 53 adjacent the top disk which is located oppositely of the pivot from the wound coil 35 so as to form a counterweight therefor. In the form of the present invention means in the form of a bracket 54 is mounted on the frame, preferably by being secured to the counterweight portion thereof, to carry a movable member, such as a pointer 55, to extend upwardly and cooperate with a scale 56 carried inside the bezel at the end of the meter. Further, the bow of the U-frame can have a post 57 extending therefrom to receive a slidable weight 58 and a post 59 can be extended from the bracket at one side of the U-frame to carry a second slidable weight 60 so that the armature can be accurately balanced.

If desired, bumper stops 61 can be provided to cooperate with the movable member or indicator.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. In a meter having a magnetic means provided with a pair of spaced pole pieces having a single air gap therebetween, an armature having a coil, and means mounting the armature for movement about an axis to move the coil in said air gap; the improvement wherein the armature has a pair of oppositely spiraled torsion springs disposed in planes at each end of the armature perpendicular to said axis and having their inner ends connected to the armature; a pair of fixed plates disposed above and below said armature, each plate being coplanar with the spring and provided with a central aperture to surround the torsion spring; and a ring-like cage for each spring having tongues passing through the central aperture to interlock therewith to rotatably mount the cage thereon, said cages protecting the springs and being connected to the other ends of said torsion springs whereby rotation of the cage adjusts the meter for zero reading.

2. In a meter having a housing enclosing magnetic means provided with a pair of flat spaced pole pieces having a single air gap therebetween, an armature, and means mounting the armature for turning movement in said air gap; the improvement wherein the armature comprises a U-shaped frame having inwardly directed pivot asse. blies mounted on the frame; insulating disks secured to the legs of the U-shaped frame with the centers of the disks located on an axis passing through said pivot assemblies; an elongate wound coil secured to the undersurface of the top disk in spaced relation to and on a radius from an axis passing through said pivots to be disposed in the air gap, said frame having an extending portion disposed oppositely from said coil to form a counterweight for the coil; a torsion spring disposed on each disk and having one end in fixed relation thereto; a pair of members fixedly carried by the meter and disposed above and below said armature, each member being provided with a central aperture to surround the torsion spring; a cage having means interlocking with the central aperture to rotatably mount the cage thereon, said cage being connected to the other ends of said torsion spring whereby rotation of the cage adjusts the meter for zero reading; means electrically connecting said coil to meter terminal means at one end of the housing; and an indicator member connected to the extending portion of the frame for movement therewith over a scale at the other end of the housing in response to energization of the coil by a source of electrical energy disposed across said terminal means.

3. In a meter having a magnetic means provided with a pair of spaced pole pieces having a single air gap therebetween, an armature, and means mounting the armature for turning movement with respect to said air gap; the improvement wherein the armature comprises a U-shaped frame having a wound coil thereon to cooperate with said pole pieces and having inwardly directed pivot assemblies on the legs of the U; top and bottom insulating disks secured to the top and bottom of the U-shaped frame with the centers of the disks aligned with an axis passing through the pivot assemblies; means connected to a terminal for the coil having a lug for fixing one end of a torsion spring, disposed over the disk, to the armature; a pair of insulating members carried by the meter and disposed above and below said armature, each member being provided with a central aperture to surround the torsion spring; a cage for each member having means interlocking with the central aperture to rotatably mount the cage thereon, said cages being connected to the other ends of said torsion spring whereby rotation of the cage adjusts the meter for zero reading; means electrically connecting said cage to terminal means for said meter; and indicator means connected to the armature for indicating the movement thereby in response to energization thereof by a source of electrical energy disposed across said terminal means.

4. In a meter having a magnetic means provided with a pair of spaced pole pieces having a single air gap therebetween, an armature, and means mounting the armature for turning movement in said air gap; the improvement wherein the armature comprises a U-shaped frame having the legs thereof provided with opposed insulating bushings carrying inwardly directed pivot assemblies; top and bottom insulating disks secured to the outside of the legs of the U-shaped frame with the centers of the disks surrounding said bushings; an elongate wound coil secured to the undersurface of the top disk in an offset spaced relation to and on a radius from an axis passing through said pivots, with one long side of the wound coil disposed in the air gap; an electrical connector press fit on each of the bushings and having a means connected to a terminal for the coil and a lug for connection to the inner end of a torsion spring disposed on the disk; a pair of non-magnetic insulating members carried by the meter and disposed above and below said armature, each member being provided with a central aperture to surround the torsion spring; an electrically conducting cage for each spring having tongues passing through the central aperture in the member to interlock therewith to rotatably mount the cage thereon, said cages being connected to the other ends of said torsion spring whereby rotation of the cages adjusts the meter for zero reading; means electrically connecting said cages to terminal means for said meter; and a member connected to the armature for movement therewith in response to energization of the coil by a source of electrical energy disposed across said terminal means.

5. In a meter having a magnetic means provided with a pair of spaced pole pieces having a single air gap therebetween, an armature, and means mounting the armature for turning movement in said air gap; the improvement wherein the armature comprises a U-shaped frame having opposed insulating bushings mounted on the legs of the U and carrying inwardly directed pivot assemblies; top and bottom insulating disks secured to the outer sides of the legs of the U-shaped frame with the centers of the disks surrounding said bushings; an elongate wound coil secured to the undersurface of the top disk in spaced relation to and on a radius from an axis passing through said pivots, with one leg of the wound coil disposed in the air gap, said frame having a counterweight extending oppositely from said coil to counterbalance the armature; an electrical connector press fit on each of the bushings, each having a means connected to a terminal for the coil and a lug for connection to one end of a torsion spring disposed on the adjacent disk; a pair of insulating members fixedly carried by the meter and disposed above and below said armature, each member being provided with a central aperture to surround the torsion spring; a cage having means interlocking with the central aperture to rotatably mount the cage thereon, said cage being connected to the other ends of said torsion spring whereby rotation of the sage adjusts the meter for zero reading; means electrically connecting said cage to terminal means for said meter; and an indicator member connected to the armature for movement therewith in response to energization of the coil by a source of electrical energy disposed across said terminal means.

6. In a meter having a housing enclosing magnetic means provided with a pair-of flat spaced pole pieces having a single air gap therebetween, an armature, and means mounting the armature for turning movement in said air gap; the improvement wherein the armature comprises a U-shaped frame having inwardly directed pivot assemblies mounted at the end of the legs of the U-frame; insulating disks secured to the legs of the U-shaped frame with the centers of the disks located on an axis passing through said pivot assemblies; an elongate wound coil secured to the undersurface of the top disk in spaced relation to and on a radius from an axis passing through said pivots to be disposed in the air gap, said frame having an extending portion disposed oppositely from said coil to form a counterweight for the coil; a torsion spring disposed on each disk and having one end in fixed re lation thereto and electrically connected to said coil; a pair of insulating members fixedly carried by the meter and disposed above and below said armature, each member being provided with a central aperture to surround the torsion spring; a cage having means interlocking with the central aperture to rotatably mount the cage thereon, said cage being connected to the other ends of said torsion spring whereby rotation of the cage adjusts the meter for zero reading; means electrically connecting said cage to meter terminal means at one end of the housing; and an indicator member connected to the extending portion of the frame for movement therewith over a scale at the other end of the housing in response to energization of the coil by a source of electrical energy disposed across said terminal means, said indicator member and said frame having angularly related adjustable weight means for balancing said armature.

7. In a meter having a magnetic means provided with a pair of spaced pole pieces providing an air gap, an armature having a coil, and means mounting the armature for movement about an axis to move the coil in said air gap, the improvement wherein the armature has a pair of spiraled torsion springs disposed in planes at each end of the armature perpendicular to said axis and having their inner ends connected to the armature; a pair of fixed plates disposed above and below said armature, each plate being coplanar with the spring and provided with a central aperture to surround the torsion spring; and a ring-like cage for each spring rotatably mounted on the plate to surround the spring, said cages protecting the springs and being connected to the other ends of said torsion springs whereby rotation of the cage adjusts the meter for zero reading.

8. In a meter having a magnetic means provided with a pair of spaced pole pieces having an :air gap, an armature having a coil, and means mounting the armature for movement about an axis to move the coil in said air gap; the improvement wherein the armature has a pair of thin planar members overlying the ends thereof and oppositely spiraled torsion springs disposed in plates at each end of the armature adjacent said planar members and perpendicular to said axis and having their inner ends connected to the armature; a pair of fixed plates disposed above and below said armature, each plate being coplanar with the spring and provided with a central aperture to surround the torsion spring; and a ring-like cage for each spring rotatably mounted on the plate to surround the spring, said planar members and cages closely confining and protecting the springs :and said cages being connected to the other ends of said torsion springs whereby rotation of the cage adjusts the meter for zero reading.

9. In a meter having a housing enclosing magnetic means provided with a pair of flat spaced pole pieces having an air gap therebetween, an armature, and means mounting the armature for turning movement in said air gap; the improvement wherein the armature comprises a Ushaped frame having pivot means on the frame for mounting the frame for pivotal movement about a predetermined axis; an elongate wound coil mounted on the frame in spaced relation to and on a radius from the axis passing through said pivot means so as to be disposed in the air gap; a torsion spring disposed adjacent each end of the armature and having one end in fixed relation thereto; a pair of members fixedly carried by the meter and disposed above and below said armature, each member having a portion coplanar with the spring and being provided with a central aperture to surround the torsion spring; a ring-like cage having means interlocking with the central aperture to rotatably mount the cage thereon, said cage being connected to the other end of said torsion spring whereby rotation of the cage adjusts the meter for zero reading; means electrically connecting said coil to meter terminal means at one end of the housing; and an indicator member connected to the extending portion of the frame for movement therewith over a scale at the other end of the housing in response to energization of the coil by a source of electrical energy dis posed across said terminal means.

References Cited in the file of this patent UNITED STATES PATENTS 627,908 Davis et a1 June 27, 1899 1,788,872 Helgeby Jan. 13, 1931 2,396,538 Schmied Mar. 12, 1946 2,438,027 Young Mar. 16, 1948 2,871,450 Podoloif Jan. 27, 1959 UNITED STATES PATENT OFFICE fiERTIFICATE 0F CORRECTION Patent No. 3, 155,906 November 3 1964 Charles G. Roper It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent. should read as corrected below Column 4, line 53, strike out "an"; column 5, line 24,

for "sage" read cage column 6, line 19, for "plates" read planes Signed and sealed this 16th day of March 1965.

(SEAL) Attes t:

ERNEST 'W. SWIDER' EDWARD J. BRENNER "n gOfficer Commissioner of Patents 

1. IN A METER HAVING A MAGNETIC MEANS PROVIDED WITH A PAIR OF SPACED POLE PIECES HAVING A SINGLE AIR GAP THEREBETWEEN, AN ARMATURE HAVING A COIL, AND MEANS MOUNTING THE ARMATURE FOR MOVEMENT ABOUT AN AXIS TO MOVE THE COIL IN SAID AIR GAP; THE IMPROVEMENT WHEREIN THE ARMATURE HAS A PAIR OF OPPOSITELY SPIRALED TORSION SPRINGS DISPOSED IN PLANES AT EACH END OF THE ARMATURE PERPENDICULAR TO SAID AXIS AND HAVING THEIR INNER ENDS CONNECTED TO THE ARMATURE; A PAIR OF FIXED PLATES DISPOSED ABOVE AND BELOW 